1. Field of the Invention
The present invention is directed to waste-water treatment. It particularly concerns improvements in the use of septic tanks.
2. Background Information
Although many residents in the more-developed countries are served by common waste-water treatment facilities, individual septic systems provide that function for a large number of other residents. A residence or other waste-water source discharges its waste into a septic tank. Settling causes a relatively clear liquid layer to form between settled-out solids and buoyant materials that form a "mat" on top of the liquid layer. Water drains from the liquid layer into, say, a leach field. In the better-functioning systems, the leach field largely purifies the water before it reaches a water table from which well water is drawn.
Although septic systems have been quite effective in a large number of installations, many factors combine to make their capacities only marginal in many cases. Because of increases in population density and other siting factors, leach-field capacities have often been so low as to cause restrictions on shower and toilet use. This has resulted in large-scale efforts to reduce shower-head flow rate and per-flush water use. Few of these measures have been beneficial from the standpoint of user convenience and some have been counter-productive even as conservation measures. Moreover, even leach fields that seem to have more than adequate leaching capacity have often proved not to purify water adequately. So a great need has developed to increase septic-system improvement.